This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A203358 #9 Jun 04 2018 05:47:33 %S A203358 5,61,565,5677,55517,547897,5390325,53087833,522656405,5146261573, %T A203358 50669762053,498898530085,4912170264077,48365462156161, %U A203358 476208363192837,4688768398640689,46165815830098469,454550623943557645 %N A203358 Number of n X 4 binary arrays with every 1 immediately preceded by 0 to the left or above. %C A203358 Column 4 of A203362. %H A203358 R. H. Hardin, <a href="/A203358/b203358.txt">Table of n, a(n) for n = 1..210</a> %F A203358 Empirical: a(n) = 5*a(n-1) +42*a(n-2) +54*a(n-3) +23*a(n-4) -7*a(n-5). %F A203358 Empirical g.f.: x*(5 + 36*x + 50*x^2 + 20*x^3 - 7*x^4) / (1 - 5*x - 42*x^2 - 54*x^3 - 23*x^4 + 7*x^5). - _Colin Barker_, Jun 04 2018 %e A203358 Some solutions for n=5: %e A203358 ..0..0..0..0....0..0..0..1....0..1..0..1....0..1..0..1....0..1..0..0 %e A203358 ..0..0..0..1....0..1..0..0....1..0..0..1....0..1..1..0....0..1..1..0 %e A203358 ..1..1..1..0....0..0..0..1....0..1..1..0....0..1..0..0....1..0..1..1 %e A203358 ..0..1..0..0....0..0..0..0....0..0..0..1....1..0..0..1....0..0..0..1 %e A203358 ..1..0..0..1....0..0..0..1....0..0..1..0....0..0..1..0....0..1..0..1 %Y A203358 Cf. A203362. %K A203358 nonn %O A203358 1,1 %A A203358 _R. H. Hardin_, Dec 31 2011